1. Technical Field
The present disclosure relates to an engine mount for a vehicle, and more particularly, to an engine mount having a bracket coupling hook made of plastic.
2. Description of the Related Art
In general, a reduction in weight of a vehicle is an important factor in designing the vehicle, and the weight reduction is not only related directly to an improvement in fuel economy, but also related to a collision performance and assembly durability of the vehicle.
Recently, even in the field of an engine mount for fixing an engine to a vehicle body of a vehicle, developments include utilizing an aluminum or plastic material instead of steel in order to reduce a weight of the mount.
In this case, an important design factor for implementing a mount made of a plastic material is the assembly durability of the mount. Because plastic is more disadvantageous in terms of strength and tolerance than steel or aluminum, a part made of plastic must be securely assembled.
For example, there has been proposed a technology in which a cover, which covers a lower part of the mount on which components such as a nozzle plate and a diaphragm are installed, is made of a plastic material, and the cover and a body of the mount are coupled by forming a latch (hook) and a fastening portion to ensure the assembly durability. In this case, a lower portion of a main rubber body (a rubber part of the mount) to which the latch is fastened is curled and finished with an aluminum material having a high elongation percentage in order to ensure the assembly durability.
However, an aluminum material having a high elongation percentage is comparatively expensive and disadvantageous due to low strength or rigidity, and an aluminum material having a low elongation percentage has high strength or rigidity, but has a problem in that a crack may be formed in the curled portion of the main rubber body because of the low elongation percentage, which increases a defect rate.
Hence, there has also been proposed a technology in which a bracket, which has a body that is made of an aluminum material and has an inner wall surface processed to mesh with a lower portion of a main rubber body, is forcibly press-fitted with an outer portion of the main rubber body such that the lower portion of the main rubber body and the inner wall surface of the bracket are forcibly press-fitted with each other.
This technology is advantageous in improving rigidity and reducing costs because it is not necessary to use an aluminum material having a high elongation percentage, but increased processing costs are required to cast the bracket because the body itself is made of the aluminum material, and there is a concern that a crack may be formed in the processed surface and fatigue strength of the bracket may deteriorate as a continuous and excessive load is applied to an outer portion of the bracket since the bracket made of aluminum is forcibly press-fitted.